I have a standard 1956 car with a standard 948cc engine.
Would it be possible to fit a large bore exhaust system to it without changing exhaust manifold? I could weld the bigger bore section to the existing down pipe? If its not possible and I change the exhaust manifold would I have performance issues with the engine as its not modified in any way?
I love the sound of my car but wish it was a little louder

If I replaced the exhaust with a bigger diameter pipe and kept the centre box where it was would it still give me the Morris minor fart..?
I have read on this forum that if you buy a big bore exhaust from the usual places, they come with a back box and this gets rid of the Morris minor fart.....??
Cheers